"It's quite literally my dream come true because I've been obsessed with Disney princesses since I was a little girl, as most little girls are," Bell told me the other night at the premiere of her new action comedy Hit & Run. "I studied music in college, so this is a very, very real dream for me coming true."

Robert Lopez, who cocreated the Broadway smash Book of Mormon with South Park's Matt Stone and Trey Parker, has written original songs for Frozen with his wife, Kristen Anderson-Lopez. "The music is exceptional," Bell said.

The flick isn't set to be released until November 2013, but Bell and Menzel have already recorded some tunes together. "It's just unbelievable," Bell said of singing alongside Menzel. "It's bone-chilling is what it is—bone-chilling!"